问题

import pandas as pd
from lets_plot import *
LetsPlot.setup_html()

data = pd.read_csv('https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/mpg2.csv')

ggplot(data, aes(x="engine horsepower", y="miles per gallon")) + geom_point(aes(color="origin of car"))

In R, using ggplot2, I would manually set the colors by writing:

... + scale_color_manual(values = c("US" = "red", "Asia" = "green", "Europe" = "blue")

How can I do the same in Python with lets-plot?

<details>
<summary>英文:</summary>

My code is:

import pandas as pd
from lets_plot import *
LetsPlot.setup_html()

data = pd.read_csv('https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/mpg2.csv')

ggplot(data, aes(x="engine horsepower", y="miles per gallon")) + geom_point(aes(color="origin of car"))

And the output is:
[![enter image description here](https://i.stack.imgur.com/8D6qN.png)](https://i.stack.imgur.com/8D6qN.png)

In `R`, using `ggplot2`, I would manually set the colors by writing:

... + scale_color_manual(values = c("US" = "red", "Asia" = "green", "Europe" = "blue")

How can I do the same in `Python` with `lets-plot`?

`lets-plot` reference manual for this function doesn't seem to help: [here](https://lets-plot.org/pages/api/lets_plot.scale_color_manual.html?highlight=scale_color_manual#lets_plot.scale_color_manual)

</details>


# 答案1
**得分**: 2

以下是您要翻译的内容：

基本上，`lets-plot` 中的操作与 R 类似。使用 pandas Series，您可以创建类似 R 中的命名向量：

```python
import pandas as pd
from lets_plot import *
LetsPlot.setup_html()

data = pd.read_csv('https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/mpg2.csv')

ggplot(data, aes(x="engine horsepower", y="miles per gallon")) + \
    geom_point(aes(color="origin of car")) + \
    scale_color_manual(values=pd.Series(["red", "green", "blue"], 
                                      index=['US', 'Asia', 'Europe']))

import pandas as pd
from lets_plot import *
LetsPlot.setup_html()

data = pd.read_csv('https://raw.githubusercontent.com/JetBrains/lets-plot-docs/master/data/mpg2.csv')

ggplot(data, aes(x="engine horsepower", y="miles per gallon")) + \
    geom_point(aes(color="origin of car")) + \
    scale_color_manual(values = pd.Series(["red", "green", "blue"], 
                                          index=['US', 'Asia', 'Europe']))